[10:06:04] [Server thread/INFO]: This server is running CraftBukkit version git-Spigot-6ee12f6-33d5de3 (MC: 1.8) (Implementing API version 1.8-R0.1-SNAPSHOT)
[10:06:05] [Server thread/INFO]: [ExtraHardMode] Loading ExtraHardMode v3.6.4

-----------------------------------------------------------------------------------------------------
[12:28:40] [Server thread/ERROR]: Could not pass event CreatureSpawnEvent to ExtraHardMode v3.6.4
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:305) ~[spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at org.bukkit.craftbukkit.v1_8_R1.event.CraftEventFactory.callCreatureSpawnEvent(CraftEventFactory.java:275) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at net.minecraft.server.v1_8_R1.World.addEntity(World.java:1014) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at net.minecraft.server.v1_8_R1.SpawnerCreature.a(SpawnerCreature.java:182) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at net.minecraft.server.v1_8_R1.WorldServer.doTick(WorldServer.java:214) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:756) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:634) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:537) [spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_31]
Caused by: java.lang.IllegalArgumentException: Cannot measure distance between world_nether and world
	at org.bukkit.Location.distanceSquared(Location.java:461) ~[spigot.jar:git-Spigot-6ee12f6-33d5de3]
	at com.extrahardmode.module.EntityHelper.arePlayersNearby(EntityHelper.java:310) ~[?:?]
	at com.extrahardmode.features.monsters.MonsterRules.onEntitySpawn(MonsterRules.java:94) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor64.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_31]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_31]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:301) ~[spigot.jar:git-Spigot-6ee12f6-33d5de3]
	... 12 more